Pressure accumulators are widely used in many types of hydraulic systems. One type of pressure accumulator comprises a thimble-shaped flexible bladder mounted in a rigid housing, and which serves to separate the interior of the housing into two separate compartments which are sealed from one another. A "liquid" port is provided at one end of the housing which communicates with one of the compartments, termed the "liquid" compartment; and a valved "gas" port is provided at the other end of the housing which communicates with the other compartment, termed the "gas" compartment.
A compressible gas, such as nitrogen, is permanently charged and compressed under high pressure and sealed through the valved gas port into the gas compartment of the accumulator. Then, an incompressible hydraulic liquid under high pressure is pumped through the liquid port into the liquid compartment. The flexible bladder is gradually forced into the gas compartment as the liquid is pumped into the liquid compartment, thereby compressing the gas in the gas compartment until a balanced high pressure is reached in both compartments. In this way, energy is stored or absorbed into the gas compartment of the accumulator, and this energy acts as a spring to force the imcompressible hydraulic liquid out through the liquid port, thereby causing the hydraulic liquid to do useful work.
It is the usual practice to provide a spring loaded poppet in the liquid port of the accumulator to prevent the bladder from extruding out of the accumulator. Under normal operation this poppet valve is held open by the spring and is closed by the action of the bladder impinging upon the poppet after all of the liquid is expelled from the liquid compartment thus preventing the gas pressure from forcing the bladder out of the liquid port.
Problems have been encountered in the prior art in providing an appropriate mounting structure for the poppet valve assembly in the liquid port. It is undesirable merely to thread the housing into the liquid port, in that the threads may become worn and stripped with the likelihood of blowing out of the valve assembly when high pressures are attained within the container, which could cause severe injury.
Various types of retainers for the valve assembly have been suggested in the prior art. For example, Mercier Pat. No. 2,801,067 discloses one type of closure valve for the oil port of a pressure accumulator which includes a tubular housing which is retained in the liquid port by means of a deformable locking ring which engages a shoulder on the housing, and which also engages the inner lip of the liquid port. A subsequent U.S. Pat. No. 3,439,712 of Mercier shows another locking arrangement in which rigid arcuate segments are used to define a locking ring to engage the shoulder on the tubular valve housing and also to engage the lip of the liquid port, and which also includes a ring of resilient material bond to the top surfaces of the annular segments and extending outwardly around the lip of the liquid port.
Another Mercier U.S. Pat. No. 3,148,705 shows a locking ring assembly similar in some respects to the arrangement described in the preceding paragraph, but one in which the segments are shaped to extend into an annular recess in the resilient ring, so that the assembly may be held in place without the necessity for bonding the ring to the annular segments.
The assembly of the present invention is of the same general type described in the Mercier U.S. Pat. No. 3,148,705, in that a resilient ring is held assembled to the arcuate segments without bonding. However, this is achieved in the assembly of the present invention in a improved and more simplified manner.